JPH095151A - Knife-ring joint - Google Patents

Abstract

PROBLEM TO BE SOLVED: To achieve a higher weighing accuracy with a lowering of mechanical friction of a weighting device by arranging a clearance at an intermediate point between a knife ring formed as joint and the surface of a cylinder while a flexible element is arranged on both sides of the knife ring to prevent the action of the knife ring in the direction of a long axis of the surface of the cylinder. SOLUTION: A joint used in a weighing device is formed as knife ring joint 1 and a small clearance is provided between a cylinder-shaped sleeve 2 with a diameter A acting as an opposed surface and a knife ring 3 having a bore diameter B. This clearance allows sufficient angular changes X horizontally and sufficient angular changes Y vertically. A flexible material 4 such as rubber or steel spring is arranged on both sides of the ring 3 to hold the ring 3 so as not to be separated from a fixed position. Thus, all motions but those caused by the angular changes X and Y, for example, motion generated on the long axis of the surface of the cylinder can be prevented by the material 4.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a knife ring joint, and it is an object of the present invention to reduce mechanical friction in a measuring instrument used for casting a molten material and increase the measuring accuracy. The knife ring is designed to be pressed as a ring against a cylindrical surface acting as an opposing surface, and any movement of the cylindrical surface in the longitudinal direction is prevented by the flexible element.

[0002]

BACKGROUND OF THE INVENTION Casting of molten material such as metal and its associated metering is important when casting, for example, metal anodes. This is because the next processing step after anode casting is electrolysis, in which case one condition for achieving high efficiency is uniform quality both in terms of anode shape and weight. Uniform quality is required to have virtually no significant effect on electrolysis when the weight error is ± 1% or less.

[0003]

Anode casting is carried out by tilting a ladle by means of a hydraulic cylinder which tilts the cradle and adjusts the casting ladle above it. The cradle and the other end of the hydraulic cylinder mesh with the bridge. The cradle, hydraulic cylinder and bridge are suspended and supported by a complex lever device which transforms the vertical force towards the ladle into a force measurable by one or several traction sensors.

As mentioned above, the horizontal force towards the floating portion of the meter is offset by the leaf spring. These springs can only receive traction. At least 6 if all twists and movements need to be prevented
Requires springs.

Only the leaf springs, which are resistant to traction, can be replaced by a restraint device with articulations at each end. The restraint device is capable of receiving both traction and compression forces and replaces two leaf springs. The use of three restraints instead of leaf springs in the scale reduces the need to adjust the leaf spring clearance. 1
The floating bridge over one or a few sensors is rigidly attached to the housing to minimize lateral movement that is detrimental to the sensor.

Friction at the joint, if it maintains its magnitude and does not fluctuate randomly, is a hindrance,
All possible load variations occur in the same direction. However, the expected movement of the ladle and the molten metal in it will lead to fluctuations in the load, especially in the initial and final weighing, when the measurement results need to be of the highest accuracy. The control program of the scale can take into account any linear error of the scale, but no random error can be observed.

One solution to fluctuating friction appears to be a ball and socket joint in which the bearing is realized with balls arranged between the two sides. Such joints appear to be superior to ordinary ball and socket joints.
This is because normal forces act on rolling friction much less than sliding friction. However, in the static state, such a ball and socket joint functions only in one direction, so that in a meter it is necessary to adjust the joint in the horizontal plane with the axis of rotation. This type of ball and socket joint must be well protected from corrosion and require regular maintenance.

From the point of view of the operation of the meter, it is essential that the forces present in the restraint device do not influence the resistance of the joint. In the ideal case, the resistance should always be the same so that the resistance only appears as a linear error and can be easily corrected.

Another solution, in which the resistance does not vary significantly with the variation of the reaction force, appears to be the rubber sleeve used in the support arms of motor vehicles. However, the properties of the rubber change and if the elastic clearance of the joint is too wide, the meter will begin to wobble. Fluctuations and fluctuations in the scale position influence the measurement results and therefore it is not permissible to have large elastic clearances in the joint.

The elastic gap can be eliminated by applying the knife pan principle. Knife pan bearings are a commonly used bearing application method for weighing machines. This type of bearing has a sharply sharpened knife made of a very hard material, the blade of which is pressed into a V-shaped groove made of the same material. In such a bearing, if the edge of the blade is normal and there is no scrap in the groove, no resistance will occur.

According to the invention, a knife ring coupling is formed in which the knife is made in the shape of a ring, the opposing surface of which is a cylindrical surface, so that it behaves equally in all directions.
Some flexible material keeps the knife ring in place, thus eliminating the need for grooves on the opposing surface. The joint according to the invention requires no maintenance and its functional parts are protected from dirt and dust.

[0012]

SUMMARY OF THE INVENTION The main novel feature of the present invention is, as will be apparent in the claims, that in a knife ring fitting for use in a meter in connection with a restraint device, the fitting is a ring-like knife. Formed and pressed against a cylindrical surface acting as an opposing surface, in which case there is a gap between the knife ring and the cylindrical surface, and flexible elements are arranged on both sides of the knife ring in the longitudinal direction of the cylindrical surface. Characterized by preventing any movement of the knife ring of.

[0013]

The present invention will now be described in more detail with reference to the accompanying drawings.

The operation of the knife ring joint 1 is based on a small clearance between a cylindrical sleeve 2 having a diameter A, which serves as the facing surface, and a knife ring 3 having a hole diameter B. As its name implies, knives are ring-like in shape. Due to this gap, a sufficient angle change X in the horizontal direction and a sufficient angle change Y in the vertical direction are possible. A flexible material 4 is arranged on both sides of the knife ring, which holds it in place when it is about to move away from its home position, and therefore any motion other than that caused by an angular change, for example the length of the cylindrical surface. Prevents shaft movement. This flexible material may advantageously be a spring made of rubber or steel, for example.

FIG. 2 shows the state in which compressive strain is directed to the joint. When the traction strain is toward the joint, the gap is located on the opposite side of the sleeve.

The state in which the knife ring joint is arranged on the outside of the sleeve that serves as the facing surface has been described above. Another feasible solution is to adjust the knife ring fitting inside the sleeve, in which case the inner surface of the sleeve serves as the facing surface.

The knife ring joint allows a small angle change required for the mechanism of the weighing machine, and the force generated in the knife ring to resist the angle change is basically independent of the compressive force or traction force toward the joint. I am trying.

In practice, the knife ring joint is implemented so that its outer dimensions correspond to standard ball and socket joints. The edge 5 of the knife blade is wide and rounded to withstand the load without breaking. The joint clearance allows for an angle change of 2-15 °, preferably about 5 °. If the angle change is about 5 ° and the sleeve diameter is 30 mm, the gap is about 0.03 mm, which means that the gap is practically invisible.

[0019]

According to the invention, the resistance caused by the joint can be removed from the weighing result, so that the result obtained is that in the case of a ball and socket joint, which is commonly used in restraint devices for measuring instruments, i.e. It is more accurate than using a joint that depends on the compressive or traction forces present in the joint, and these forces cause changes in frictional momentum. Experiments have shown that this new knife ring joint has 4-10 times better hysteresis characteristics than ball and socket joints.

The joint of the present invention is used for transmitting force or for constraining the element to be weighed in place in all applications of the meter using one or several restraint devices. You can Apart from the metering of the molten material, the invention can of course be applied for other purposes.

[Brief description of drawings]

FIG. 1 is a side view of a knife ring joint of the present invention.

FIG. 2 is a view of a cross section AA of FIG. 1 seen from above.

[Explanation of symbols]

 1 Knife ring joint 2 Cylindrical sleeve 3 Knife ring 4 Flexible element 5 Knife blade edge

Claims (7)

[Claims] 1. A joint for use in a weighing machine in connection with a restraint device, which joint is pressed against a cylindrical surface which is formed as a ring-like knife and serves as an opposing surface, in which case
A gap is provided between the knife ring and the cylindrical surface, and flexible elements are arranged on both sides of the knife ring to prevent any movement of the knife ring in the longitudinal direction of the cylindrical surface. Characteristic knife ring joint. 2. The joint according to claim 1, wherein the edge of the knife ring is wide and rounded. 3. The knife ring joint according to claim 1, wherein the clearance of the joint can be changed by 2 to 15 °. 4. The knife ring joint of claim 1, wherein the knife ring is located outside the cylindrical surface. 5. The joint according to claim 1, wherein the knife ring is located inside the cylindrical surface. 6. The knife ring joint according to claim 1, wherein the flexible element is made of rubber. 7. The joint according to claim 1, wherein the flexible element is made of a steel spring.